Recently, silver halide color photosensitive materials have been improved in photosensitivity and image quality, and also researches have been made for improvement in the field of rapid processing.
Processing of photosensitive materials essentially consists of two processes, a color development process and a deslivering process. The deslivering process usually consists of a bleaching process and a fixing process, or a bleach-fix process. In processing of photosensitive materials, a water washing process and a stabilization process are optionally included in addition to the above-mentioned processes.
Various kinds of methods have been proposed to increase the processing speed. In order to increase the processing speed of photosensitive materials, there have been introduced various improvements in such fields as a composition of silver halide, a layer thickness, a coupler, and various kinds of additives. It has been known that the improvement by means of the composition of silver halide is effective in both the color developing process and the desilvering process. Especially, it is generally known that silver bromide or silver bromoiodide with a low content of silver iodide is effective in increasing the speed of development and improving desilvering. However, in the case of changing simply the composition of silver halide, the processing stability tends to deteriorate while the processing speed is increased. Controlling the stability of development has become increasingly important with the recent spread of mini-laboratories for photo-finishing and the tendency of low replenishment of a color developing solution.
On the other hand, because photosensitive materials for amateur use are exposed to various conditions in temperature and humidity, an aging stability of photosensitive materials has been an important subject up to this time. Especially when silver bromide or silver bromoiodide with a low content of silver iodide is used, degradation of the properties during preservation has been a serious problem. It is assumed that the degradation is caused by adsorption and desorption of spectral sensitizers or other additives to silver halide grains, and various kinds of things have been attempted to solve the problem, which has not yet been solved completely.
In order to increase a sensitivity of the photosensitive materials, various methods are proposed, such as incorporating AgX grains with a larger size, using a diequivalent coupler, and reforming a layer structure. The diequivalent coupler tends to be preferably used because it can reduce processing time and provide rapid processability attributable to a thinner layer thickness achieved by a reduced amount of silver halide as well as an improved sensitivity, while a sharpness of a formed dye image is improved. But, the diequivalent coupler tends to increase fluctuation of developing performances in an ordinary development process, and to degrade a preservability of the photosensitive materials.
Accordingly, stability in processing and improvement of preservability are indispensable to the photosensitive materials when a diequivalent coupler is used.
In the invention, it has been found that stability in processing and preservability can be simultaneously improved by using the photosensitive silver halide whose halide composition is regulated, in combination with a particular diequivalent coupler.